Smart high-temperature aging system

The present invention relates to a smart high temperature aging system for a battery cell.

The present application claims the benefit of priority based on Korean Patent Application No. 10-2021-0088257 dated Jul. 6, 2021, and all the entire contents of the Korean patent application are incorporated herein by reference.

Recently, secondary batteries capable of being charged and discharged have been widely used as energy sources for wireless mobile devices. In addition, the secondary batteries are getting attention as energy sources for electric vehicles and hybrid electric vehicles which are proposed as measures to address the air pollution of conventional gasoline and diesel vehicles using fossil fuels. Therefore, types of applications using the secondary batteries are diversifying due to the advantages of the secondary batteries, and it is expected that the secondary batteries are applied to more fields and products in the future than now.

Secondary batteries may be classified into lithium ion batteries, lithium ion polymer batteries, and lithium polymer batteries according to the composition of an electrode and an electrolyte, and among these batteries, the use of the lithium ion polymer battery, which is less prone to leakage of the electrolyte and easy to manufacture, is increasing. Generally, according to a shape of a battery case, the secondary battery is classified into a cylindrical battery in which an electrode assembly is installed in a cylindrical metal can, a prismatic battery in which an electrode assembly is installed in a prismatic metal can, and a pouch-type battery in which an electrode assembly is installed in a pouch-type case of an aluminum laminated sheet. The electrode assembly installed in the battery case is formed with a structure of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode and is a power generation element capable of being charged and discharged. The electrode assembly is classified into a jelly-roll type electrode assembly in which a separator is interposed between a positive electrode and a negative electrode, which are long sheets coated with an active material, and is wound, and a stack type electrode assembly in which a plurality of positive and negative electrodes, each having a predetermined size, are sequentially stacked with a separator interposed therebetween.

In the secondary battery, an activation process is generally performed after electrolyte injection, and in the activation process, a battery cell forms a solid electrolyte interface (SEI) film through initial charging and then metal foreign materials are rapidly eluted through high-temperature aging to prevent a low voltage failure from being generated.

Since the high-temperature aging is generally performed at a temperature of 60° C. or higher, work should be performed in a space in which the temperature is kept constant. However, according to the related art, after loading trays on which a plurality of battery cells are mounted, temperature control is performed using a general thermometer. However, in this case, among the battery cells in the high temperature aging chamber, a temperature of a battery cell in a central portion of the tray is excessively increased due to difficulty in thermal circulation compared to a battery cell in an outer portion. In this case, a phenomenon in which a capacity of the battery cell located in the central portion is degraded due to an irreversible reaction occurs. In addition, when the temperature control is performed by a person, it is difficult to uniformly control the temperature, and since all the work should be performed manually, there is a problem in that a lot of time and money are required.

An object of the present invention is to provide a smart high temperature aging system provided with an algorithm capable of minimizing a temperature deviation inside a tray during a high temperature aging process.

In one embodiment of the present invention, there is provided a high temperature aging system including a high temperature aging chamber, a battery cell tray stack comprising a plurality of stacked battery cell trays, each battery cell tray including a plurality of battery cells, one or more tray racks located in the high temperature aging chamber, each rack including a grid-shaped storage space in which the battery cell tray stack is located, a stacker crane configured to transport one of the battery cell trays or the battery cell tray stack to the grid-shaped storage space, a thermal imaging camera located on the stacker crane, the thermal camera being configured to acquire thermal image temperature data on the battery cell tray stack loaded in the grid-shaped storage space, and a controller configured to control a temperature inside the high temperature aging chamber on the basis of the thermal image temperature data.

The stacker crane may include a mast configured to move in a left-right direction and a loading station installed on the mast and configured to vertically move, and the thermal imaging camera may be further configured to acquire thermal image temperature data of the battery cell trays while moving together when the mast and the loading station are moved.

One or more heaters and one or more blowing fans may be located in the high temperature aging chamber to control the temperature inside the high temperature aging chamber.

The controller may be further configured to calculate temperatures of a central portion and an outer portion of the battery cell tray stack from the thermal image temperature data and control the temperature inside the high temperature aging chamber on the basis of the calculated temperatures.

When the temperature of the central portion of the battery cell tray stack or a temperature difference between the central portion and the outer portion of the battery cell tray stack is outside a reference range, the controller may be configured to control the temperature inside the high temperature aging chamber.

Each tray rack may include a plurality of battery cell tray stacks. The controller may be configured to calculate an average value of the temperature of the central portion of the battery cell tray stacks located in the tray rack or an average value of the temperature difference between the central portion and the outer portion of the battery cell tray stacks located in the tray rack, and when the calculated average value of the temperature of the central portion of battery cell tray stacks located in the tray rack or the average value of the temperature difference between the central portion and the outer portion of the battery cell tray stacks located in the tray rack is outside a reference range, the controller may be configured to control the temperature of the entire high temperature aging chamber.

The controller may be configured to calculate an average value of the temperature of the central portion of the battery cell tray stacks located in a portion of the tray rack or an average value of the temperature difference between the central portion and the outer portion of the battery cell tray stacks located in the portion of the tray rack, and when the calculated average value of the temperature of the central portion of the battery cell tray stacks located in the portion of the tray rack or an average value of the temperature difference between the central portion and the outer portion of battery cell tray stacks located in the portion of the tray rack is outside a reference range, the controller may be configured to locally control a temperature of a region in which a corresponding battery cell tray stack of the portion of the tray rack is located.

The control of the temperature inside the high temperature aging chamber may be performed by stopping and restarting one or more of the heaters and the blowing fans or by a combination of the stopping and restarting of the one or more of the heaters and the blowing fans.

When decreasing the temperature inside the high temperature aging chamber, the controller may be configured to stop operation of the one or more heaters and operates the one or more blowing fans.

When increasing the temperature inside the high temperature aging chamber, the controller may be configured to operate the one or more heaters and stop the operation of the one or more blowing fans.

The controller may be configured to learn the thermal image temperature data to derive a temperature control algorithm for minimizing a temperature difference between a central portion and an outer portion of the battery cell tray stack.

The controller may be configured to collect the thermal image temperature data to configure training data and the controller may include artificial intelligence configured to derive the temperature control algorithm.

The artificial intelligence may be configured to verify validity of the derived temperature control algorithm by comparing a predicted temperature according to the derived temperature control algorithm and the thermal image temperature data of an actual battery cell tray stack and to update the training data with the verification result.

The temperature control algorithm may relate to positions and numbers of the heaters or the blowing fans operating or stopping or may relate to control of an operating time of one or more of the heaters or the blowing fans.

The artificial intelligence may be formed of a deep neural network (DNN) for deep learning.

In accordance with the present invention, a temperature inside a high temperature aging chamber is optimally controlled on the basis of an artificial intelligence algorithm so that, during a high-temperature aging process, a temperature deviation in the tray can be automatically minimized, and thus it is possible to reduce energy consumption and improve the performance of a battery cell.

Hereinafter, the present invention will be described in detail. Before describing the present invention, terms or words used herein and the appended claims should not be construed to be limited to ordinary or dictionary meanings, and should be construed in accordance with the meaning and concept consistent with the technical spirit of the present invention according to the principle in that inventors can properly define concepts of terms in order to describe their inventions with the best manner.

In the present application, the terms “comprising,” “having,” and the like are used to specify the presence of a feature, a number, a step, an operation, a component, an element, or a combination thereof described herein, and they do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, elements, or combinations thereof. In addition, when a portion of a layer, a film, a region, a plate, or the like is referred to as being “on” another portion, this includes not only a case in which the portion is “directly on” another portion but also a case in which still another portion is present between the portion and the other portion. Contrarily, when a portion of a layer, a film, a region, a plate, or the like is referred to as being “under” another portion, this includes not only a case in which the portion is “directly under” another portion but also a case in which still another portion is present between the portion and the other portion. In addition, in the present application, being disposed “on” may include the case of being disposed not only on an upper portion but also on a lower portion.

Hereinafter, the present invention will be described in detail.

are schematic diagrams illustrating a high temperature aging system according to the present invention.is a schematic diagram illustrating a process in which the battery cell tray stack is accommodated in a tray rack.

Referring to, a high temperature aging systemaccording to the present invention includes a battery cell tray stackin which battery cell trays accommodating a plurality of battery cells inside are stacked in multiple stages therein, one or more tray racksaccommodated inside a high temperature aging chamberand each including a grid-shaped storage space in which the battery cell tray stackis accommodated, a stacker craneconfigured to transport the battery cell tray to the grid-shaped storage space, a thermal imaging camerainstalled on the stacker craneand configured to acquire thermal image temperature data on the battery cell trays loaded in the grid-shaped storage space, and a controllerconfigured to control a temperature inside the high temperature aging chamber on the basis of the thermal image temperature data.

As described above, according to the present invention, the temperature of the high temperature aging chamber is controlled on the basis of the thermal image temperature data, and as will be described below, the temperature control process is performed on the basis of an artificial intelligence algorithm so that energy can be saved and the performance of the battery cell can be improved.

Hereinafter, each configuration of the high temperature aging system will be described in detail.

are schematic diagrams illustrating structures of a battery cell tray and a battery cell tray stack.

In the present invention, a high temperature aging process is performed in the high temperature aging chamberof which the inside is kept constant at a high temperature, and a plurality of battery cellsare subjected to the high temperature aging process at one time. To this end, the plurality of battery cellsare mounted on the battery cell trayin which the plurality of battery cellsmay be disposed at regular intervals.

Partition walls may be installed inside the battery cell trayto form grid-shaped storage spaces, and the battery cellsmay be disposed in the spaces partitioned by the partition walls in a one-to-one manner. In, although the battery cellhas been illustrated as a cylindrical battery cell, there is no particular limitation on a shape of the battery cell, and various types of battery cells such as a prismatic battery cell or a pouch-type battery cell may be used. In this case, the shape of the partition wall inside the battery cell traymay be changed according to the shape of the battery cell.

Battery cell traysare stacked in multiple stages as a set for space utilization in the high-temperature aging process to form the battery cell tray stack. In, although it is illustrated that six battery cell traysare stacked to form one battery cell tray stack, the number of battery cell traysforming the battery cell tray stackis not particularly limited.

Any material may be used as the battery cell trayas long as it cannot be deformed in a high-temperature aging environment. For example, any of metal materials, such as iron and aluminum, and polymer materials such as polycarbonate and acryl may be used.

Referring toalong with, one or more tray racksmay be provided in the high temperature aging chamberso as to accommodate the battery cell tray stack. The tray rackhas a structure in which grid-shaped storage spaces are formed like a bookshelf to accommodate the battery cell tray stack. The grid-shaped storage spaces are formed in a predetermined number of rows and stages, and in, although the grid-type storage spaces have been illustrated as being formed in nine rows×five stages, there is no particular limitation on the sizes and numbers of the grid-type storage spaces.

The battery cell tray stackis transported to the grid-shaped storage space of the tray rackand then stored at a high temperature for a predetermined time. The stacker cranetransports the battery cell trayto the grid-shaped storage space. In this case, the battery cell traymay be transported in the form of an individual battery cell tray or may be stacked in the form of the battery cell tray stackand then transported to the storage space at one time.

In the present invention, the stacker craneincludes a mastmoving in a left-right direction and a loading stationinstalled on the mastto vertically move. The stacker craneincludes a traveling cartconfigured to move in the left-right direction along one side of the tray rack at a bottom of the high temperature aging chamber. The traveling cartincludes wheels in rolling contact with a floor surface. In this case, in order to allow the traveling cartto move in a state of maintaining a constant distance between the tray rackand the stacker crane, a guide rail (not shown) may be formed in a movement path on which the traveling cartis moved.

The mastis mounted on the traveling cartin the form of an upright column, supports the loading station, and provides a path on which the loading stationvertically moves. In addition, a guide groove (not shown) for causing the loading stationto vertically move may be formed on the mast.

The loading stationmay have a plate shape and may be a part on which the battery cell trayis mounted during the transport process, and a wheel (not shown) capable of being inserted into a guide groove (not shown) is coupled to a surface coupled to the mastso that the loading stationmay vertically move on the mastalong the guide groove. The loading stationmay vertically move on the mast, and the mastmay move along the guide rail by the traveling cartin the left-right direction to load or unload the battery cell trayinto or from a desired space.

One or more heatersand one or more blowing fansare installed in the high temperature aging chamberto control a temperature inside the high temperature aging chamber. In order to uniformly increase and decrease the temperature of the high temperature aging chamber, the heatersor the blowing fansmay be disposed in a uniform pattern along a wall surface and a ceiling of the high temperature aging chamber. To this end, as described below, when the temperatures of some of the battery cell tray stacks disposed in the storage space is excessively increased or decreased, the blowing fanor the heaterof a corresponding battery cell tray stack is operated so that the temperature inside the high temperature aging chamber may be controlled through heat convection. Although the heaterand the blowing fanare illustrated as being alternately disposed in, the present invention is not limited thereto, and it is also possible to control the temperature through the blowing fan after placing the heater on one side of the high temperature aging chamber.

Meanwhile, the thermal imaging camerais installed on the stacker craneand acquires thermal image temperature data on the battery cell tray stackloaded in the grid-shaped storage space. Specifically, the thermal imaging cameraacquires thermal image temperature data on the battery cell trays while being moved with the mastand the loading stationfor loading or unloading of the battery cell trays. For example, the thermal imaging cameramay be provided in the form of being coupled to the loading station. In this case, as the mastmoves in the left-right direction and the loading stationvertically moves, the battery cell tray stackmay be smoothly photographed.

Specifically, the thermal imaging cameraphotographs a surface of the battery cell tray stackand displays a temperature distribution for each region through color. In this way, it is possible to simultaneously measure the temperatures of two or more points of a measurement target. Further, since a consecutive check of a temperature between each point is possible using the thermal imaging camera, it is possible to intuitively or qualitatively grasp a temperature distribution of the entire region of the measurement target. For example, a portion having a relatively low temperature may have a darker color than a portion having a high temperature. Alternatively, respective temperatures in the temperature distribution may be expressed in different colors so that a portion having a high temperature may be expressed as red and a portion having a low temperature may be expressed as relatively blue.

According to the present invention, since the thermal imaging camerais used to capture a temperature image of the battery cell tray stack, a temperature distribution of the entire measurement target is captured on one screen compared to using a conventional thermometer so that it is possible to measure the temperature of not only one point of the measurement target but also the entire region of the measurement target. As described below, this makes it easier to grasp a temperature difference between the central portion and the outer portion of the battery cell tray stackwith one photograph and to easily grasp the temperature of the central portion rather than using a thermometer.

The controllermay be a computing device, and when the thermal image temperature data is acquired by the thermal imaging camera, the controllercontrols the temperature inside the high temperature aging chamberon the basis of the thermal image temperature data.

The controllerconverts a thermal image into a specific temperature value to acquire thermal image temperature data on the outer portion. A method in which the controller converts an image captured by the thermal imaging camera into a specific temperature value may be performed by a conventional computing device or program.

Then, the controllercalculates temperatures of the central portion and the outer portion of the battery cell tray stack from the thermal image temperature data.

As shown in, the battery cell tray stackin which the battery cell trays are stacked in multiple stages is loaded into the grid-shaped storage space in the tray rack. In this case, during the high-temperature aging process, thermal circulation is difficult in a central portion A of the battery cell tray stackdue to surrounding structures (other battery cell trays) so that a temperature of the central portion A is higher than the outer portion. The controllercontrols the temperature of the high temperature aging chamber on the basis of the temperature data of the central portion and the outer portion of the battery cell tray stack.

The controllercontrols the temperature of the high temperature aging chamberon the basis of the temperature of the central portion of the battery cell tray stackor a temperature difference between the central portion and the outer portion of the battery cell tray stack. Specifically, when the temperature of the central portion of the battery cell tray stackor the temperature difference between the central portion and the outer portion of the battery cell tray stackis outside a reference range, the controllercontrols the temperature inside the high temperature aging chamber. Here, the reference range is a temperature range determined to be an appropriate value and may be an item to be appropriately controlled according to specifications of the battery cell, a size of the battery cell, a size of the storage space, and the temperature of the high temperature aging chamber. For example, when the temperature of the central portion of the battery cell tray stackis higher than the reference range or the temperature difference between the central portion and the outer portion is higher than the reference range, the controller may stop heating the high temperature aging chamberand lower the temperature inside the high temperature aging chamber.